Bioavailability and bioequivalence are parameters that are often elusive to a pharmaceutical formulations scientist. The scientist is faced with many industry and regulatory constraints in which formulations are developed. In particular, there are composition patent constraints to which one skilled in the art must formulate around in order to achieve a pharmaceutically accepted bioequivalent product.
The present invention is directed to compositions for topical or transdermal delivery of active pharmaceutical agents and methods of using compositions. In particular, the present invention has achieved significant advancement in utilization of a preferred combination of crosslinked polyvinylpyrrolidone with or without the addition of silicon dioxide to achieve a desired drug release of an active pharmaceutical ingredient (API) in a transdermal drug-in-adhesive patch formulation.